A Unitized Piston Design for Hydraulic Cylinder Applications 790830
A new unitized piston design provides important opportunities for progress in mobile equipment hydraulic cylinder applications.
Improved bearing and sealing characteristics and tighter dimensional tolerances permit shorter cylinders and permit higher working hydraulic pressures, which in turn permit use of smaller, lighter, more energy efficient hydraulic equipment.
In production, a steel body has nylon bearing material injection molded onto the OD. A groove machined in the periphery retains a rubber loader ring and a teflon piston seal ring.
Tests demonstrate negligible piston seal ring wear, volumetric efficiency better than 99.998 percent (dynamic), and drift less than 0.0015 in. (0.0381 mm) per hour (static).